1. Field of the Invention
The invention relates to a passive electric component suitable for SMD-technique and having a cylindrical supporting member or a supporting member in the form of a rectangular parallelepiped and having electric connection elements at its ends.
2. Description of the Prior Art
It is known to contact passive electric components having, for example, a cylindrical supporting member, with connection caps which are provided at the end faces of the supporting member and to which connection wires are welded (FIG. 1).
Modern methods of mounting components use the possibility of soldering the components directly to conductor tracks of printed circuit boards without the use of connection wires. Said technology is used to an ever increasing extent under the indication "Surface Mounted Device" (SMD).
Components, in particular resistors and capacitors suitable for the SMD technique, are manufactured in two different constructions: as a so-called chip component and as a so-called MELF component. Chip components generally have supporting members in the form of rectangular parallelepipeds which have end faces suitable for soldering. MELF components (MELF=Metal Electrode Face Bonding) start from cylindrical supporting members having connection caps in which the connection wires are omitted and the caps themselves are made suitable for soldering at their surfaces by an electroplating treatment and are soldered directly with said connection caps to conductor tracks of printed circuit boards (FIG. 2).
The great advantage of the SMD technology is that extremely high packing densities of components on the printed circuit boards are possible. For realizing over increasing densities, smaller and smaller components suitable for the SMD technique become necessary.
Limits are imposed in two respects upon the miniaturization of passive components of the type mentioned in the preamble; first of all, supporting members and connection contacts cannot be made smaller arbitrarily for mechanical reasons and hence manufacturing reasons, secondly, such components cannot be made smaller arbitrarily with a view to required electrical characteristics.